Western blotting/Immunoblotting
     Technique for detecting specific proteins 
   separated by electrophoresis by use of 
   labeled antibodies.
   Allows to identify a particular protein of 
   interest among many proteins in a sample.
    Introduced by Towbin, et al. in 1979 and is 
   now a routine technique for protein analysis. 
   The specificity of the antibody-antigen 
   interaction enables a single protein to be 
   identified in the midst of a complex protein 
   mixture. 
    Flow chart of Western blotting
             Electrophoresing the protein sample
            Assembling the Western blot sandwich
        Transferring proteins from gel to nitrocellulose paper
              Staining of transferred proteins
     Blocking nonspecific antibody sites on the nitrocellulose paper
        Probing electroblotted proteins with primary antibody
        Washing away nonspecifically bound primary antibody
      Detecting bound antibody by horseradish peroxidase-anti-Ig 
     conjugate and formation of a diaminobenzidine (DAB) precipitate
              Photographing the immunoblot
   SDS polyacrylamide-gel electrophoresis (SDS-PAGE)
       Sodium Dodecyl Sulfate- Polyacrylamide 
               Gel Electrophoresis (SDS-PAGE)
        Stands for “SDS Polyacrylamide Gel Electrophoresis
       1) Thin gel separates molecules on the basis of size.
       2) Negatively charged molecules are loaded into wells 
        in
            a gel that is submerged in buffer.
       3) Electrical current is applied to the gel, causing the
           molecules to move toward the positive electrode (the 
         anode, usually marked red).
       4) Smaller molecules move faster through the gel 
        than
             larger molecules
       Thus, smaller molecules will be found at the bottom 
        of the gel and larger molecules will be found at the 
        top of the gel.